Reduce event listeners in KQuickStyleItem

David Edmundsonrequested to merge
work/d_ed/event_filters into master

We have lots of KQuickStyleItem's in a given app.

Each item has an event filter for all events on both QGuiApplication and QWindow.

Even though every event filter is extremely fast we have many many events being processed many times during the application lifetime to the point that event filters stacks up to be noticable.

This patch reduces things to one event filter per window.

Merge request reports